The original Lagoon covered most of today’s township, including the Racecourse and further north.
The Lagoon was a major breeding area for whitebait and aquatic birds.
In 1838 settlement of the area began with whalers and sealers, then progressed to family groups, numbers markedly increased during the gold rush years (1860’s).
In the 1860’s areas around Post Office Creek, the race course and township were drained.
The causeways were originally built between 1881-1883 as a precursor to further draining of the land for farming. The local community of the time put a stop to any further draining.
In 1912 The Hawksbury Lagoon became a Reserve for Native and Imported Game (in effect a Wildlife Refuge). It has remained under DOC protection since this time.
The surrounding area was originally covered in flax, sedges and rushes. There were 3 flax mills in Waikouaiti during the early days of European settlement.
There are two main areas of the Lagoon:
- South of the causeway has a large body of water approximately 0.5m deep separated by a causeway. The water level is controlled by two culverts.
- Post Office Creek and the north arm are more tidal and have an intermittent opening to the sea.
There are, at different times of the year, large numbers of birds using the lagoon as a stop off place in their migration or for nesting.
Birds include: Shoveller Duck, Grey Teal, Paradise Ducks, Shelduck, White Heron, Royal Spoonbills, Shags, Pied Stilts, Black Swans and Geese.
Water quality has deteriorated over the years as a result of leaching from surrounding soils and from activity such as nearby landfill sites. Problems are compounded by a low throughput of water, sediment uptake, low water level, low oxygen levels and lack of covering vegetation.
The Hawksbury Lagoon is administered by the Department of Conservation, with a number of other agencies also involved including: The Maori Reserves Trustees, the Dunedin City Council and the Otago Regional Council. It is considered a significant and increasingly rare example of an estuarine wetland.